Manufacture of oxidation products of acenaphthene



Patented Nov.22, i927. I 1,649,833 UNITED STATES PATENT OFFICE.

HARRY F. LEWIS, OF BUFFALO, NEW YORK, ASSIGNOR T NATIONAL ANILINE & CHEMICAL COMPANY, INC., 0! NEW YORK, N. 1., A CORPORATION OF NEW YORK.

MANUFACTURE OF OXIDATION PRODUCTS 01 ACENAPHTEENE. llo Drawing. Application filed January 24, 1921. Serial No. 439,600. I

This invention relates-to an improved The improved process of the. present inmethod or process for the manufacture .of vention. can be carried out with difierent oxidation products ofacenaphthene and metal oxides as catal tic agents, and more more articularly to the manufacture of particularly oxides 0 such metals as form 6 acenapllthylene from acenaphthene and the oxides of different degrees of oxidation. 60 manufacture of acenaphthaquinone and Among the metal oxides that are of particunaphthalic anhydrid from acenaphthene or lar value in the process of the present invenhth l t1o n may be mentloned oxides of manganese,

It is known that acenaphthene can be oxides of molybdenum and oxides of vana- 10 oxidized by such oxidizing agents as an acid dium, In a limited measure, however, the 65 solution of sodium dichromate, but the same or similar catalytic effects are also methods commonly employed for this OXlshown the oxides of other metals such as dation involve the use of costly oxidizing reiron, mc el, cobalt, etc. agents, while the products obtained are fre- I have further discovered that the catalyquently produced in forms which make the tie oxidation of acenaphthene can be regu- 7D roducts difiicult to separate and purify. lated, for example, by regulation of the tem- 1 oreover, naphthalic anhydrid is not directperature and the particular'metal oxide emly produced by such wet oxidation methods, ployed as a catalytic agent, so that acebut naphthalic acid is produced instead of naphthylene can be obtained as the main 9 the anhydrid, and requires heating and product of the oxidation, or so that naphdehydration to give the anhydrid therefrom. thahc anhydrid. can be obtained as the main This heatin and dehydration, moreover, is product of the oxidation. For example, accompanie with some decomposltion of manganese dioxide is of special value for the naphthalic acid or anhydrid. use in the production of acenaphthylene, by

It has also been proposed to produce carrying out the oxidation of the acenaphacenaphthylene from acenaphthene by the thene at a suitably regulated temperature,

, action of lead oxide at high temperatures, for example, between 300 and 450 C. The the lead oxide furnishing the oxygen for the present invention, accordingly, involves imoxidation; and also to effect the production provements in the production of acenaphthyof acenaphthylenefrom acenaphthene by the lene, as well asthe production of naphthalic action of high temperatures in the presence anhydrid, by the catalytic oxidation of aceof vapors of carbon dioxide; but the manunap thene in the manner described. facture of acenaphthylene by such methods The invention includes also certain imis a diificult and tedious task, and the prodprovements in the se aration of naphthalic note obtained by these methodsare frequentanhydrid and acenapfithylene where both of 90 1y diflicult to separate and purify. these products .are' produced in notable The present mvention largely overcomes amounts during the catalytic'oxidation. I or minimizes the objections and difiiculties have found that, by suitable regulation of of such prior proposals, and enables the the condensation of the vapors resulting oxidation of acenaphthene for example to be from the catalytic oxidation of acenaphcarried out in a simple and advantageous thene, the na hthalic anhydrid can be frac manner, for the production therefrom, for extionall con ensed first, at a temperature ample, of acenaphthylene or naphthalic anaroun 100 to 200 (1, while the acenaphhydrid as the main products of the process. thylene and unchanged acenaphthene will The present invention is based upon the pass on uncondensed and can be subsequentdiscoverythat acenaphthene can be readily 1y condensed at a lower temperature in a oxidized by heating the acenaphthene until separate condenser. Where naphthalic anit passes into the vapor phase, mixing the hydrid is thus desired as the main roduct acenaphthene vapor, either during or subof the process, it can be directly pr need in 59 sequent to its production, with an oxygena state of ,relativel high purity, and the containing gas mixture such as air, and passacenaphthylene and unchanged acenaphing the resulting mixture over finely divided thene which are subsequently condensed can metal oxides as catalytic agents at an elebe returned to the process for reuse, so that vated temperature appropriate to the'catathe acena hthylene, as well as the acenaphlytic oxidation. thene, wi undergo further catalytic oxidation for the production of naphthalic anhydrid therefrom. The present invention, accordingly, includes improvements in the oxidation of acenaphthylene, as well as of acenaphthene, for the production of naphthalic anhydrid therefrom. I

In general, the temperature range within which the process of the present invention should be kept is within therange of from 200 to 600 C. If the temperature is too low, the process does not take place with sufiicient rapidity or completeness, While if the temperature is too high, objectionable over-oxidation or decomposition is liable to take place with decrease in the yields of the product or products desired. In practice, it will usually be more advantageous not to let the temperature fall much below 300 or to raise it very greatly above 500. So also, as above noted, the course of the reaction canbe regulated, to a certain extent, by regulation of the temperature; lower temperatures, with oxides of vanadium molybdenum and manganese, being more favorable to the production of acenaphthylene, and highertemperatures with these same oxides being more favorable to the production of naphthalic anhydrid. Other oxidation products than acenaphthylene and naphthalic anhydrid may also be produced. For example, acenaphthaquinone may be produced in varying amounts and may be recovered as a product of the operation. It may thus be separated out, by fractional condensation at an intermediate temperature between that of separation of the naphthalic anhydrid and that of separation of the acenaphthylene and acenaphthene; or it can be separated from the naphthalic anhydrid or acenaphthylene or both by suitable methods of separation.

The invention Will be further illustrated by the following more detailed description of certain specific example thereof:

EwampZe.Acenaphthene in the vapor phase and air are allowed to mix in a heated chamber, using a considerable excess of the,

aire. g. 9 to 12 volumes, over and above the proportion theoretically required to oxidize the acenaphthene to acenaphthylene, and the mixture of heated air and acenaphthene vapor is passed into a reaction chamber maintained at a temperature ranging from 300 to 450 C., and preferably at a temperature of about 400 C. In this chamber the gas mixture is forced into contact With'oxides of manganese in the form of fine powder, for example, supported on trays where the current of mixed gases may ass over and through it. a The gases are. ept under a slight pressure suflicient to cause them to flow continuously through the reaction chamber. The product of the reaction consists mainly of a'cenaphthylene admixed with some unconverted acenapht ene. This product is condensed in a suitable condenser and thus recovered in a solid state. The acenapht-hylene can be separated from the acenaphthene by sublimation and fractional condensation and the acenaphthene used over again in the process.

If the reaction is carried out at higher temperatures, for example, 500 C., with oxides of manganese as the catalytic agent, naphthalic anhydrid is formed to some extent, but this particular catalytic agent, i. e., oxides of manganese, I have found to be particularly advantageous for use in the production of acenaphthylene from acenaphthene, rather than for the production of naphthalic anhydrid. Acenaphthylene can similarly be produced, with oxides of vanadium and molybdenum, particularly at lower temperatures, around 300, While at higher temperatures, e. g., around 400 to 475 (1, naphthalic anhydrid is formed in relatively large amount, or mixtures consisting mainly of acenaphthylene and naphthalic -anhydrid in varying amounts. With iron oxide as the catalytic agent, a mixture of acenaphthylene and naphthalic anhydrid, can similarly be produced, but the yields are usually lower, and I regard the use of iron oxide as less advantageous. The oxides of nickel and cobalt are of more tion of naphthalic anhydrid as the main product of the oxidation.

The metal oxides may be used in. the form powders and suitably supported, for example, on trays in such a manner that the mixed gases or gases and vapors may pass over or through the oxide or oxides. Instead of using the metallic oxides alone, they may be admixed with other substances which may either be inert in character and serve as carriers for the oxides, or which may even contribute to the catalytic oxidation, such as silica, magnesium oxide or other alkaline earth oxides, pumice, etc. So also, the gaseous mixture can be brought into contact with the catalytic material or passed therethrough, in various ways. The form or type of apparatus employed for carrying out the particular value for the produc materially above oxidation, as well as the means for heating the gases and catalytic material, or the reac- 'tion chamber in which the reaction takes place, can also be varied, and the reaction chamber heated, for example. electrically, or

by products of combustion, or by direct heat,

so that the naphthalic anhydrid will be di-' rectly obtained in a relatively pure state. This can be readily effected by passing the vapors resulting fromthe reaction through a condenser maintained at a regulated temperature between about 100 and 200 0., at which temperature the naphthalic anhydrid condenses, while the acenaphthylene and unchanged acenaphthene pass on and can be subsequently condensed in the cooled portion of the condenser, or in a condenser at a lower temperature, for example, at temperatures not exceeding about C. or even at room temperature. The naphthalic anhydrid is thus obtainable in a relatively pure state, while the acenaphthene and acenaphthylene which are condensed together can be returned to the process and used in the next run. By thus returning the acenaphthylene, together with unchanged acenaphthene, the naphthalic anhydrid becomes the main product of the process, and, by retreating the acenaphthylene and unchanged acenaphthene, the yield of naphthalic anhydrid can be correspondingly increased, and a high yield or efficiency of conversion, based upon the total acenaphthene originally used, can thus be obtained.

Where acenaphthylene is thus returned for further treatment, it is vaporized along with the unchanged acenaphthene and the combined vapors, in admixture with air, and

reheated to an appropriate temperature, are then subjected to further oxidation in the reaction chamber, by the use of an oxidizing agent such as manganese dioxide, and a further production of naphthalic anhydrid brought about. The present invention, accordingly, includes the catalytic oxidation of acenaphthylene for the production of naphthalic anhydrid therefrom, as well as the catalytic oxidation of acenaphthene for the production of either acenaphthylene or naphthalic anhydrid, or a mixture of both, etc.

Where acenaphthaquinone is produced in appreciable amount in admixture with the other products of oxidation, it can be, separated in any suitable manner, for example, naphthalic anhydrid can be se arated from the acenaphthaquinone by disso ving out the anhydrid with alkali. When the acenaphthaquinone is mixed with acenaphthylene, the acenaphthaquinone can be dissolved out of the mixture with sodium bisulfite.

It will thus be seen that the present invention is of more or tion for the production of different products of oxidation, such as acenaphthylene, naphthalio anhydrid, etc., from acenaphobtain an increased less general applica-- thene, or of naphthalic anhydrid from acenaphthylene; and involves the catalytic oxidation of the acenaphthene or acenaphthylene in the vapor phase, using oxygencontaining gases as the oxidizing agent and catalytic material such as the oxides of manganese. The process of the invention is capable of some variation, as well as regulation, for example, in the ratio of air or other oxygen-containing gas to the vapor of the acenaphthene, the temperature of oxidation, the particular catalytic agent employed, etc., so that one or another product may be produced as the primary product of the process. I have thus found it possible to produce either naphthalic anhydrid or acenap-hthylene with yields of 90% and higher, based on the original acenaphthene employed.

Instead of using air as the oxygen-containing gas, gaseous mixtures richer in oxygen, or oxygen itself, can be used, to

rate of oxidation, or the air may be mixed with a gas which is relatively inertunder the conditions of the process.

The process of the present invention can, be carried out at substantially atmospheric pressure or preferably with a slight excess of pressure of the mixed gas and vapor sufficient to cause the gas and vapor to flow continuously through the reaction chamber at the appropriate rate. The process can, however, be carried out at pressures other than atmospheric, for example, under a reduced pressure of greater well as under a pressure considerably in excess of atmospheric.

I claim:

l. The method of producing a'cenaphthy-v I lene, which comprises subjectin acenaphthene in the vapor phase to oxidation with an oxygen-containing gas in the presence of oxide of manganese.

2. The method of producing acenaphthyllene, which comprises subjecting acenap thene in the vapor phase to oxidation with atmospheric air in the presence of oxide of manganese at temperatures within the range of about 300 to 450 C.

,3. The method of producing ace'naphthylene, which comprises subjecting a'cenap thene in the vapor phase to oxidation with atmospheric air in the presence of oxide 0 manganese at a In testimony whereof I afiix my signature.

- HARR Y F. LEWIS.

or decreased degree or or less degree, as Y f temperature of. about 

